Of 20 necropsy patients with fatal osteogenic sarcoma, 4 had metastases to the heart. One had recurrent ventricular tachycardia, 1 had anatomic evidence of aortic regurgitation due to massive periortic neoplastic infiltration which prevented coaptation of aortic cusps during ventricular diastole, 1 had massive invasion of the peri-superior vena cava tissue and typical clinical features of the superior vena caval syndrome, and one had neoplastic obstruction of the inferior vena cava as it entered the thorax. Among patients with either primary or secondary neoplasms to the heart, osteogenic sarcoma is unique because the metastases contain bone and, therefore, may be radiographically visible, they are usually large and often intracavitary.